This invention relates to a device for operating on those types of tire which enable the vehicle to travel even in the case of a puncture or of insufficient inflation pressure.
Tires of the stated type, such as so-called System Pax tires produced by the MICHELIN Company enable the vehicle to travel even when their inflation pressure is very low or close to zero.
These tires, which are described in French patent application FR 92/15061 and FR 93/14702, comprise not only the outer carcass but also a separate toroidal support ring of elastomer rubber, which is housed in an appropriate seat provided in the well of the wheel rim.
When the tire is removed from the wheel rim, said toroidal ring remains inside said outer carcass, hence to replace or repair the carcass said toroidal support ring has to be extracted and then reinserted.
To extract the ring from and then replace it into the outer carcass requires considerable force on the part of the operator, this force being mainly due to the rigidity of said elastomer ring and the rigidity of the carcass, and is also partly due to the uncomfortable position in which the operator is compelled to work.
The object of the present invention is to solve the stated drawbacks within the framework of a rational and reliable solution.
The invention attains said object by providing a device which enables the toroidal ring to be extracted from the carcass, and then reinserted therein, automatically without the operator needing to apply any physical force.
The device of the invention can be associated with a tire removal machine or be a separate accessory.
Said device comprises a lower base provided on one side with means for supporting in the correct working position the tire outer carcass from or into which said toroidal ring is to be extracted or inserted, and provided on the opposite side with means for extracting or inserting said toroidal ring. Said means for supporting the tire outer carcass are adjustable in height to enable the tire to be positioned in the correct working position.
Said means for extracting or inserting said toroidal ring comprise a pneumatic or hydraulic cylinder-piston unit, with the rod of which there is associated at least one tool provided with at least one appendix for gripping the edge of said ring.
In a preferred embodiment said rod presents two appendices for gripping the edge of said ring, one provided to grip the edge of said ring only during its extraction from the tire outer carcass, and the other provided to grip said ring only during its insertion into the tire outer carcass.
The special characteristics of the invention are stated in the claims.